Generally speaking, the main premise behind fantasy baseball dynasty and keeper leagues is simple: Each owner keeps a pre-determined number of players from year-to-year. That’s where most of the similarities end, however. The draft allows you to add fresh talent and perhaps even reserves in the form of minor leaguers each season, but for the majority of teams, the core players are already in place heading into draft day. For the purposes of this piece, we will stick to offering up draft strategy tips, though the number of keepers for each league, the "penalties" for keeping them (i.e. losing a pick in the round they were drafted last year or having their auction price increase), and the length for which you can keep them can all vary wildly and have a big impact on your specific draft.

One basic tip: Knowing your league rules can’t be stressed enough. Yes, that's true for every kind of fantasy league, but it's especially true for dynasty/keeper leagues. The most common and easily fixable mistakes are drafting without an understanding of how players should be valued in each league. Keeper and dynasty leagues both involve needing additional years of value from potentially everyone you draft or bid on, so it’s important to know exactly how the keeper rules work.

The answer to most of these questions for a dynasty league is that there are no limits on how many players one can keep and no limits for how long you can keep them. You draft a guy and keep him until you decide you no longer want him. But that doesn’t mean that you can go drafting guys with reckless abandon and hope everything works out. That’s a recipe for disaster. It arguably takes more research and planning for dynasty leagues than keeper leagues because of how long you can keep a player.

Fantasy Baseball Draft Strategy: Keeper/Dynasty leagues

Drafting styles in Keeper vs. Dynasty leagues

Drafting in a dynasty league usually means there is greater value on the young players and even prospects if you are allowed to draft minor leaguers. The ability to have a guy on your team from the first or second year of his career into his prime is a great chance to really maximize your roster every season. The trick, though, is making sure you don’t miss out on a certain player. Whiffing on a big-name player in a dynasty league is akin to an NFL team missing on a QB in the first round: It can set you back a few years of being able to compete.

If you have to give up something to keep players, like picks or auction dollars, that changes things, but it still makes sense to focus on young players and mix in the proven veterans to bolster the roster. In a league where giving up a draft pick one round higher than the round the player was selected to keep him the following year, it makes sense to take fliers at the end of the draft. For example, someone who took Ronald Acuna Jr. in the 15th-20th round his first year has him for his entire career.

Keeper leagues function a little differently since there is a finite amount of players who can be kept and for specific amounts of years. The year-to-year extra cost makes keeper league owners utilize a different kind of strategy than those used in dynasty leagues.

In most leagues the keeper limit is in the range of three-to-five years, and each year there are increasing costs to keeping said player. Whether that be a higher cost in an auction format or a rise in draft pick in a snake format, it still must be considered when drafting the players in the first place. In a league in which a player can be kept for just three seasons including the draft year, an owner should try to maximize those years by focusing on potential prime years, but that doesn’t mean it’s easy to do. Again, focusing on young talent that can be acquired cheaply is almost always key to sustained success in the league.

Again, we’ll go back to knowing the league rules and how many positions are on an active roster (and a bench for that matter). The point I’m trying to make here is that you don’t want to box yourself into a corner with the keepers you select by keeping too many at one position, for example. Every year someone lets a player go they shouldn’t have, but if you keep too many guys just to fill a position, then it's more difficult to draft that breakout player who falls too far in the draft or gets underbid on in your auction. While knowing you don’t have to necessarily worry about a position heading into the draft can be nice, with the depth across the board at most positions, why take the chance on missing a guy you didn’t think would be there? This is more likely to happen in keeper leagues rather than dynasty leagues, but don’t you worry dynasty leaguers, we’re getting to you now.

Many who have played fantasy football in dynasty leagues know that the most advantageous way to construct a roster is to focus on getting young talent at thin positions. Those who took Saquon Barkley in his rookie year are set for the next several seasons with a top running back in a position where there seem to be fewer each year. The same situations can arise in baseball. The guy or girl who got their hands on Gary Sánchez a few years ago will be set at catcher for a long time, too, and getting a player like that at a shallow position is key to winning a leagues year after year.

Pitching is a slightly different story in these leagues, and one that takes a few different things into account. Obviously, no one wants to deal with a player that gets injured; however, having a pitcher who undergoes Tommy John surgery is less of an issue in a format where you can keep them forever rather than just a few years. Of course, there is always the option of dropping the oft-injured pitchers, but in keeper leagues the price is obviously higher for a guy missing a season than in a dynasty format.

Opportunity cost in a keeper league is much more of an issue than in dynasty since there are generally no prices attached to keeping a guy from year-to-year in that format. Simply keeping an ace for the sake of it rarely makes a lot of sense unless the keeper price is an actual bargain. Fantasy Alarm readers will ask us if keeping a guy like Max Scherzer or Gerrit Cole at close to double their projected auction values or for a guaranteed first-round pick is worth it. Well, why give up more than is necessary is our general argument. Sure, having a potential top-five pitcher is great, but that doesn’t mean you have to hamstring yourself to do it. The best way to construct a roster in these leagues is to look for cheap, up-and-coming guys late in the draft.

I know, I know -- I sound like a broken record. But in all honesty, staffing your roster with just a bunch of solid mid-priced pitchers will not get you anywhere in a keeper format. They won’t carry keeper value from year-to-year since you will have acquired them for basically their cost year-after-year, and odds are they won’t demonstrably help you in any category more than a cheaper guy would.

Over the past few seasons, it's become a hot topic to debate whether you should punt or specifically target saves in drafts. Based on the "Drafting Closers" piece in the Fantasy Alarm Draft Guide, none of the top-seven saves leaders in 2019 were the same as the top seven from '18, which muddies up this discussion for sure. The best strategy for dealing with relievers in terms of a keeper or dynasty format is to get one guy who has a firm grasp on the gig now, and then use late-round fliers or low-dollar bids on guys that have the upside to be a future closer or high-impact reliever.

You do not, under any circumstances, want to invest in two high-priced closers in one year. They are just too fickle, and it will hamstring your roster for the upcoming season without giving you any keeper or holdover value going forward. Plus, who's to say those high-priced guys will actually keep their closer jobs this year?

Everybody wants to win -- that’s the whole point of playing fantasy sports, isn’t it? But in keeper/dynasty leagues, unlike re-draft leagues, an owner has to have two distinct and somewhat divergent goals: Win now and build for the future. The paramount focus is winning in the year at hand, so let's see if we can’t help you figure out better ways to keep your success going.

Once again, it’s about the young, cheap players, but more than that, it’s about getting your hands on prospects. Most leagues nowadays have minor league drafts or sections on the bench to hold prospects for a length of time. If you are in a league that only lets you keep prospects for a certain number of years, getting guys that are closer to the bigs is important, but most leagues have an unlimited prospect timeline which opens the door to quite a few more options. The art of finding prospects involves more than just looking at numbers. Sure, a guy can put up huge stats in the minors, but if there isn’t a spot for him on the major league roster, he is nothing but trade bait.

Drafting prospects in typically sparse positions can be a big benefit for you down the road, like Sánchez at catcher or Acuna in the outfield. If you had either on your roster for next to nothing, imagine the extra time you could devote to other positions. Maybe you could go for that top outfielder...or stack first and third base with top-tier players...or get two aces instead of one.

Getting more extension on your budget or draft picks aren’t the only benefits to prospect-grabbing. They also give you trade pieces to help you win in the current season if you need help in a certain area. There will always be at least one owner who will buy the biggest hype about a guy and give you a very nice piece in return. Winning now is always the safer bet compared to banking on potential.

Your prospect strategy in both dynasty and keeper leagues will depend on your league’s rules and format and how other owners tend to build their rosters. So, telling you to focus on nothing but getting all ace-caliber pitching prospects or all outfielders won’t do anyone any good, but realizing who people focus on can help you on goal two. If you know that owner A, B, and C all prefer to use their prospect spots on top-flight hitting spots but owners D, E, F, G, and H all go for pitchers and nothing else, you can see that you have a lot of trading partners by charting a course of mixing targets. It also allows you to really find the diamonds in the rough in positions the other owners aren’t going after, which will help you keep your success going.

Playing in these types of leagues can really grow your baseball acumen and be a great experience for those who are interested in being more of a GM then a one-year manager. These leagues also offer challenges not present in re-draft formats, but learning the skills of balancing one-year and multi-year goals will mean nothing but success for you as you dominate your league!